Obstacle detection for a mobile automation apparatus

ABSTRACT

Obstacle detection for a mobile automation apparatus is provided. The mobile automation apparatus includes a structured light camera positioned on a support structure to detect at least a top of a shopping cart in a region adjacent to the mobile automation apparatus. The mobile automation apparatus can include other structured light cameras. Furthermore, one or more ultrasound arrays are used as secondary obstacle detector such that when the one or more ultrasound arrays detect an object, and at least one structured light camera simultaneously does not detect the object, an obstacle avoidance protocol is implemented.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority to U.S. Provisional Application No. 62/492,670 entitled “Product Status Detection System,” filed on May 1, 2017, by Perrella et al., and to U.S. Provisional Application No. 62/492,712 entitled “Obstacle Detection For A Mobile Automation Apparatus,” filed on May 1, 2017, by Arandorenko et al., all of which are incorporated herein by reference in their entirety.

BACKGROUND OF THE INVENTION

Mobile automation apparatuses are increasingly being used in retail environments to perform inventory tracking. Such mobile automation apparatuses may be equipped with various sensors to autonomously navigate paths within the retail environment and perform such tasks. During such autonomous navigation, the mobile automation apparatuses may perform ancillary tasks that include data capture, avoiding obstacles, stopping, docking, and the like. Hence, a key issue during such autonomous navigation in a retail environment is to be able to detect static obstacles and/or moving obstacles. Static obstacles include boxes, pillars, reflective stanchions, baskets, and other items found in retail environments. Moving obstacles include shopping carts, retail associates, cleaning equipment, and shoppers. Especially with obstacles such as humans and/or obstacles associated with humans, such as shopping carts, the mobile automation apparatuses must be able to detect these obstacles from a safe distance in order to stop or avoid the obstacles. These challenges are compounded in retail environments where lighting varies in different areas. Furthermore, highly reflective and/or shiny obstacle objects found in the retail environment, such as mirrors, stanchions, see-through glass doors, aisle siding, and other reflective materials, may also cause variable lighting that compounds the challenges associated with obstacle avoidance. In particular, the reflective metal lattice on shopping carts, for example, can be difficult to detect. Indeed, a single sensor by itself does not exist, at low cost, that can detect all of the complex obstacles listed above.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The accompanying figures, where like reference numerals refer to identical or functionally similar elements throughout the separate views, together with the detailed description below, are incorporated in and form part of the specification, and serve to further illustrate embodiments of concepts that include the claimed invention, and explain various principles and advantages of those embodiments.

FIG. 1 is a block diagram of a mobile automation system in accordance with some embodiments.

FIG. 2 is a side view of a mobile automation apparatus in accordance with some embodiments.

FIG. 3 is a block diagram of the mobile automation apparatus of FIG. 2 in accordance with some embodiments.

FIG. 4 is a block diagram of a control application in accordance with some embodiments

FIG. 5 is a flowchart of a method of shopping cart detection for a mobile automation apparatus in accordance with some embodiments.

FIG. 6 is a side view of the mobile automation apparatus of FIG. 2 detecting a shopping cart in accordance with some embodiments.

FIG. 7 is a flowchart of a method of obstacle detection for a mobile automation apparatus in accordance with some embodiments.

FIG. 8 is a side view of the mobile automation apparatus of FIG. 2 detecting an object in accordance with some embodiments.

FIG. 9 depicts the mobile automation apparatus of FIG. 2 implementing an obstacle avoidance protocol in accordance with some embodiments.

FIG. 10 depicts an arrangement of fields of view of structured light cameras at the mobile automation apparatus of FIG. 2 in accordance with some embodiments

Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of embodiments of the present invention.

The apparatus and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.

DETAILED DESCRIPTION OF THE INVENTION

An aspect of the specification provides a mobile automation apparatus comprising: a support structure extending in an upward direction; a navigation module configured to move the mobile automation apparatus in an environment; a structured light camera positioned on the mast, the structured light camera configured to detect at least a top of a shopping cart in a region adjacent to the mobile automation apparatus; and, a controller configured to: when the structured light camera detects the top of the shopping cart, control the navigation module to implement an obstacle avoidance protocol.

In some embodiments, the structured light camera is located at a height on the mast where the structured light camera acquires images of the top of a shopping cart in the region.

In some embodiments, the structured light camera is at an angle of 45°±5° to the mast, and at a height of between 1.3 meters to 1.8 meters up the mast.

In some embodiments, the mobile automation apparatus further comprises a base, the support structure extending in the upward direction from the base; and one or more of a depth sensing device and a LIDAR device located at the base, and configured to sense depth at an ankle height.

In some embodiments, the mobile automation apparatus further comprises one or more second structured light cameras between a base of the mast and the structured light camera, the one or more second structured light cameras configured to detect objects over respective angles on either side of the region.

In some embodiments, the mobile automation apparatus further comprises one or more ultrasound arrays on the mast, each of the one or more ultrasound arrays configured to detect objects at least in the region. In some embodiments, the controller is further configured to: when the one or more ultrasound arrays detect an object, and the structured light camera simultaneously does not detect the object, control the navigation module to implement the obstacle avoidance protocol. In some embodiments, the controller is further configured to: when the one or more ultrasound arrays detect the object, and the structured light camera simultaneously does not detect the object, control the navigation module to implement the obstacle avoidance protocol only when the object is within a threshold distance.

In some embodiments, the navigation module configured to move the mobile automation apparatus in the environment in a forward direction, and the structured light camera is further configured to detect at least the top of the shopping cart in the region in the forward direction.

In some embodiments, the obstacle avoidance protocol comprises one or more of: stopping the navigation module, slowing the navigation module and controlling the navigation module to avoid the shopping cart.

A further aspect of the specification provides a method comprising: at a mobile automation apparatus comprising: a support structure extending in an upward direction; a navigation module configured to move the mobile automation apparatus in an environment; a structured light camera positioned on the mast, the structured light camera configured to detect at least a top of a shopping cart in a region adjacent to the mobile automation apparatus; and, a controller, when the structured light camera detects the top of the shopping cart, controlling, using the controller, the navigation module to implement an obstacle avoidance protocol.

A further aspect of the specification provides a mobile automation apparatus comprising: a support structure extending in an upward direction; a navigation module configured to move the mobile automation apparatus in an environment; at least one structured light camera located on the mast, the at least one structured light camera configured to detect objects over a region; one or more ultrasound arrays on the mast, each of the one or more ultrasound arrays configured to detect the objects over the region; and, a controller configured to: when the one or more ultrasound arrays detect an object, and the at least one structured light camera simultaneously does not detect the object, control the navigation module to implement an obstacle avoidance protocol.

In some embodiments, the controller is further configured to: when the one or more ultrasound arrays detect the object, and at least one structured light camera simultaneously does not detect the object, control the navigation module to implement the obstacle avoidance protocol only when the object is within a threshold distance.

In some embodiments, the navigation module is configured to move the mobile automation apparatus in the environment in a forward direction, and at least one structured light camera and the one or more ultrasound arrays are further configured to detect the objects in the forward direction.

In some embodiments, the obstacle avoidance protocol comprises one or more of: stopping the navigation module, slowing the navigation module and controlling the navigation module to avoid the object.

In some embodiments, the structured light camera is mounted at an angle of 45°±5° to the mast, and at a height of between 1.3 meters to 1.8 meters up the mast.

In some embodiments, the one or more ultrasound arrays are further configured to detect the objects over a 360° field of view.

A further aspect of the specification provides a method comprising: at a mobile automation apparatus comprising: a support structure extending in an upward direction; a navigation module configured to move the mobile automation apparatus in an environment; at least one structured light camera located on the mast, the at least one structured light camera configured to detect objects over a region; one or more ultrasound arrays on the mast, each of the one or more ultrasound arrays configured to detect the objects over the region; and, a controller, when the one or more ultrasound arrays detect an object, and the at least one structured light camera simultaneously does not detect the object, controlling, using the controller, the navigation module to implement an obstacle avoidance protocol.

A further aspect of the specification provides a mobile automation apparatus comprising: a support structure extending in an upward direction; a navigation module configured to move the mobile automation apparatus in an environment; at least one structured light camera located on the mast, the at least one structured light camera configured to detect objects over a region; one or more ultrasound arrays on the mast, each of the one or more ultrasound arrays configured to detect the objects over the region; and, a controller, wherein when the one or more ultrasound arrays detect an object and the at least one structured light camera simultaneously does not detect the object, the controller controls the navigation module to implement an obstacle avoidance protocol.

A further aspect of the specification provides a mobile automation apparatus comprising an ultrasound sensor; a structured light camera positioned higher than the ultrasound sensor; a controller configured to compare ultrasound sensor data to structured light data; and a navigation module configured to alter the navigation of the mobile automation apparatus based on the comparison. In some embodiments, the mobile automation apparatus further comprises a communication interface configured to transmit a notification of the alteration to a mobile device. In some embodiments, the notification includes a location of the mobile automation apparatus.

FIG. 1 depicts a mobile automation system 100 in accordance with the teachings of this disclosure. Such a mobile automation system 100 may be operated in a retail facility, such as a store, supermarket, shopping mall, showroom, warehouse club, convenience store, or within a service facility such as a restaurant or pharmacy, or within a warehouse, factory, or industrial facility. The facility may include multiple shelf modules 110 positioned within the facility. The shelf modules 110 may be arranged to define a plurality of aisles. At least one zone of the facility may include shelf modules 110, aisles, walls, posts, pillars, bins, conveyors or equipment. The system 100 includes a server 101 in communication with at least one mobile automation apparatus 103 (also referred to herein simply as the apparatus 103) and at least one mobile device 105 via communication links 107, illustrated in the present example as including wireless links. The system 100 is deployed, in the illustrated example, in a retail environment including a plurality of shelf modules 110 each supporting a plurality of products 112. Each shelf module has one or more generally planar shelves, generally extending along a length of the shelf module and oriented at various vertical heights for supporting a plurality of products 112 in positions conducive to retail merchandising. Each shelf also has a front edge that may be used to position shelf merchandising materials 114 such as a price label, an electronic shelf label, shelf talker, advertising signage, or a coupon dispensing apparatus. The apparatus 103 may be deployed within the facility where it may move between one or more zones of the facility, monitoring a region in proximity to the apparatus 103. More specifically, the apparatus 103 is deployed within the retail environment, and controlled by the server 101 (via the link 107) to travel the length of at least a portion of the shelf module 110. The apparatus 103 is equipped with a plurality of data capture sensors, such as image sensors (e.g. one or more digital cameras) and depth sensors (e.g. one or more Light Detection and Ranging (LIDAR) sensors), and is further configured to employ the sensors to capture sensor data, that may be associated with a shelf module, products positioned on the shelf module, or shelf merchandising materials. In the present example, the apparatus 103 is configured to capture a series of digital images of the modules 110, as well as a series of depth measurements, each describing the distance and direction between the apparatus 103 and a point on or enclosed by a module 110.

The server 101 includes a controller 120, interconnected with a non-transitory computer readable storage medium, such as a memory 122. The memory 122 includes any suitable combination of volatile (e.g. Random Access Memory or RAM) and non-volatile memory (e.g. read only memory or ROM, Electrically Erasable Programmable Read Only Memory or EEPROM, flash memory, hard drive). In general, the controller 120 and the memory 122 each comprise one or more integrated circuits. The controller 120, for example, includes any suitable combination of central processing units (CPUs) and graphics processing units (GPUs) and/or any suitable combination of field-programmable gate arrays (FPGAs) and/or application-specific integrated circuits (ASICs) configured to implement the specific functionality of the server 101. In an embodiment, the controller 120, further includes one or more central processing units (CPUs) and/or graphics processing units (GPUs). In an embodiment, a specially designed integrated circuit, such as a Field Programmable Gate Array (FPGA), is designed to perform specific functionality of the server 101, either alternatively or in addition to the controller 120 and the memory 122. As those of skill in the art will realize, the mobile automation apparatus 103 also includes one or more controllers or processors and/or FPGAs, in communication with the controller 120, specifically configured to control navigational and/or data capture aspects of the mobile automation apparatus 103.

The server 101 also includes a communications interface 124 interconnected with the controller 120. The communications interface 124 includes any suitable hardware (e.g. transmitters, receivers, network interface controllers and the like) allowing the server 101 to communicate with other computing devices—particularly the apparatus 103 and the mobile device 105—via the links 107. In some embodiments, a link 107 may be a direct wired link, such as a cable or data bus. It some embodiments a link 107 may be a direct wireless link, such as a radio signal, infrared communication, or sound communication. In some embodiments, a link 107 may be a networked communication that traverses one or more networks, such as a local area network or wide-area network. The specific components of the communications interface 124 are selected based on the type of communication links (e.g. networks) enabled by the server 101. In the present example, a wireless local-area network is implemented within the retail environment via the deployment of one or more wireless access points. The links 107 therefore include both wireless links between the apparatus 103 and the mobile device 105 and the above-mentioned access points, and a wired link (e.g. an Ethernet-based link) between the server 101 and the access point.

The memory 122 stores a plurality of applications, each including a plurality of computer readable instructions executable by the controller 120. The execution of the above-mentioned instructions by the controller 120 configures the server 101 to perform various actions discussed herein. The applications stored in the memory 122 include a control application 128, which may also be implemented as a suite of logically distinct applications. In general, via execution of the control application 128 or subcomponents thereof, the controller 120 is configured to implement various functionality. The controller 120, as configured via the execution of the control application 128, is also referred to herein as the controller 120. As will now be apparent, some or all of the functionality implemented by the controller 120 described below may also be performed by preconfigured hardware elements (e.g. one or more ASICs) rather than by execution of the control application 128 by the controller 120.

In general, the controller 120 is configured to control the apparatus 103 to capture data, and to obtain the captured data via the communications interface 124 and store the captured data in a repository 132 in the memory 122. The server 101 is further configured to perform various post-processing operations on the captured data, and to detect the status of the products 112 on the modules 110. When certain status indicators are detected, the server 101 is also configured to transmit status notifications to the mobile device 105.

For example, in some embodiments, the server 101 is configured via the execution of the control application 128 by the controller 120, to process image and depth data captured by the apparatus 103 to identify portions of the captured data depicting a back of a module 110, and to detect gaps between the products 112 based on those identified portions. Furthermore, the server 101 is configured to provide a map and/or paths and/or path segments and/or navigation data and/or navigation instructions to the apparatus 103 to enable the apparatus 103 to navigate the modules 110.

Attention is next directed to FIG. 2 and FIG. 3 which respectively depict: a schematic side perspective view of the apparatus 103, showing particular sensors of the apparatus 103; and a schematic block diagram of the apparatus 103.

With reference to FIG. 2, the apparatus 103 generally comprises: a base 210 configured to move on wheels 212 (e.g. on a floor 213 of the environment), and the like; and a mast 214 and/or a support structure extending in an upward direction (e.g. vertically) from the base 210. However, in other embodiments, the base 210 moves on devices other than wheels, for example casters, tracks and the like.

The apparatus 103 is further provisioned with various sensors for obstacle avoidance which include, but are not limited to: a structured light camera 218 located on the mast 214, the structured light camera 218 configured to detect objects over a region, for example in a field of view of the structured light camera 218; one or more ultrasound arrays 220-1, 220-2 on the mast 214, each of the one or more ultrasound arrays 220-1, 220-2 configured to detect objects over the region in which the structured light camera 218 is configured to detect objects; one or more of a depth sensing device and a LIDAR device 221 located at the base 210, and configured to sense depth at an ankle height (e.g. over the region in which the structured light camera 218 is configured to detect objects); and one or more second structured light cameras 228 between a bottom end of the mast 214 and the structured light camera 218, the one or more second structured light cameras 218 configured to detect objects over respective angles on either side of the region (e.g. the region in which the structured light camera 218 is configured to detect objects).

It is further understood that detection of an object as described herein includes, but is not limited to, detection of a portion of an object and further understood that different sensors may detect different portions of the same object.

While not depicted, the base 210 and the mast 214 may be provisioned with other various navigation sensors for navigating in the environment in which the modules 110 are located and various further data acquisition sensors for acquiring electronic data and/or digital data associated with the modules 110, products 112, or shelf merchandising materials 114. Such data may be used for one or more of stock detection, low stock detection, price label verification, plug detection, planogram compliance and the like.

As depicted, the location and geometry of the structured light camera 218 on the mast 214 is selected such that the structured light camera 218 is configured to detect at least a top of a shopping cart in a region adjacent to the mobile automation apparatus 103. For example, the structured light camera 218 is located at a height on the mast 214 where the structured light camera 218 acquires images of a top of a shopping cart in a region adjacent the mobile automation apparatus 103. Indeed, the structured light camera 218 is generally configured to detect at least a top of a shopping cart in a region adjacent to the mobile automation apparatus 103. For example, shopping carts are generally about 0.8 m high. Hence, the structured light camera 218 may be mounted as depicted at an angle of 45°±5° to the mast 214, and at a height of between 1.3 meters to 1.8 meters up the mast 214, for example, as depicted, at about 1.5 m from a bottom of the wheels 212 or above the floor 213.

Other geometries of the structured light camera 218 are within the scope of present embodiments. However, as the structured light camera 218 is generally pointing towards the floor 213, the structured light camera 218 is generally configured to detect objects in the field of view of structured light camera 218 including objects on the floor 213 that may not be detectable by the other sensors.

The structured light camera 218 is generally configured to detect objects by projecting structured light (including, but not limited to, infrared light) onto a region, including, but not limited to one or more of vertical stripes, horizontal stripes, dots, and the like, and acquiring images of the structure light projected onto the region (including, but not limited to, infrared images). Discontinuities in the structured light detected in the acquired images indicate objects in the field of view of the structured light camera 218. In other words, the region in which objects are detected is the field of view of the structured light camera 218 that is illuminated by the projected images. Hence, the structured light camera 218 is configured to detect at least a top of a shopping cart in a field of view of the structured light camera 218, which depends on the angle and height of the structured light camera 218.

The two or more structured light cameras 228 operate in a similar fashion, but are aimed about perpendicularly away from the mast 214, however at different angles. In a particular embodiment, the two or more structured light cameras 218 are aimed without an overlap in their fields of view, with a gap therebetween being filled in by the field of view of the structured light camera 218. An example geometry of the two or more structured light cameras 228 is described below with respect to FIG. 10.

Furthermore, while the one or more ultrasound arrays 220-1, 220-2 are at least configured to detect objects over the region in which objects are detected by the structured light camera 218, in some embodiments, the one or more ultrasound arrays 220-1, 220-2 are further configured to detect the objects circumferentially around the mast 214 and/or the apparatus 103. An ultrasound array 220 may be configured to detect objects in any direction from the mast (360° detection) or only in certain angular regions around the mast 214 and/or the apparatus 103. The one or more ultrasound arrays 220-1, 220-2 are interchangeably referred to hereafter, collectively, as ultrasound arrays 220 and, generically, as an ultrasound array 220. Furthermore, in some embodiments, the ultrasound arrays 220 comprise phased ultrasound arrays.

The ultrasound arrays 220 generally operate by transmitting an ultrasound pulse and receiving reflections of the ultrasound pulse from objects in a range of the transmitted ultrasound pulse, for example in a phased manner. Indeed, each of the ultrasound arrays 220 generally comprises a plurality of ultrasound transducers arranged circumferentially around the mast 214 which transmit respective ultrasound pulses in a phased manner. Overlaps in the fields of view of adjacent ultrasound transducers can assist with pinpointing a general location of an object reflecting a respective ultrasound pulse. For example, if an object is detected by a first ultrasound transducer, but not detected by a second adjacent ultrasound transducer, the object is located in an angular region associated with only the first ultrasound transducer; however, an object detected by both the first and the second ultrasound transducers is located in an angular region within the overlapping fields of view of the two adjacent ultrasound transducers.

The LIDAR device 221 generally operates by transmitting laser pulses (e.g. an infrared laser pulse) at a plurality of known angles, and a sensor (e.g. a light sensor and/or an infrared sensor) at the LIDAR device 221 measures a distance to a point of interaction with a surface using a time-of-flight measurement. The LIDAR device 221 is generally at an ankle height, for example between about 5 cm to about 10 cm from the floor 213 and is generally configured to scan over a plane horizontal to the floor 213. Hence, the LIDAR device 221 is configured to detect wheels of shopping carts, legs of modules 110, and the like. However, other depth detecting devices may be used in place of the LIDAR device 221 in other embodiments.

Furthermore, one or more combinations of sensor data from the sensors (e.g. the structured light cameras 218, 228, the one or more ultrasound arrays 220, and the LIDAR device 221) are useable by the apparatus 103 to determine a distance of an object from each respective sensor. For example, structured light images can indicate distance of objects, as can data from LIDAR devices and ultrasound arrays.

In addition, in some embodiments, the apparatus 103 is generally configured to move in a forward direction, for example, in a direction being imaged by the LIDAR device 221. In some of these embodiments, the structured light camera 218 is further configured to detect at least a top of a shopping cart in a region in the forward direction and/or a movement direction.

Data from the various obstacle sensors at the apparatus 103 may be processed at the apparatus 103 and used to avoid obstacles including, but not limited to shopping carts.

For example, attention is next directed to FIG. 3 which depicts a schematic block diagram of further components of the apparatus 103. In particular, the apparatus 103 includes a special purpose controller 320 specifically designed to implement obstacle detection as described herein. The controller 320 is connected to a non-transitory computer readable storage medium, such as a memory 322. The memory 322 includes any suitable combination of volatile (e.g. Random Access Memory or RAM) and non-volatile memory (e.g. read only memory or ROM, Electrically Erasable Programmable Read Only Memory or EEPROM, flash memory, hard drive). In general, the controller 320 and the memory 322 each comprise one or more integrated circuits. The controller 320, for example, includes any suitable combination of central processing units (CPUs) and graphics processing units (GPUs) and/or any suitable combination of field-programmable gate arrays (FPGAs) and/or application-specific integrated circuits (ASICs) configured to implement the specific functionality of the apparatus 103. Further, as depicted, the memory 322 includes a repository 332 for storing data, for example data collected by sensors 330. In an embodiment, the controller 320, further includes one or more central processing units (CPUs) and/or graphics processing units (GPUs). In an embodiment, a specially designed integrated circuit, such as a Field Programmable Gate Array (FPGA), is designed to implement obstacle detection as discussed herein, either alternatively or in addition to the controller 320 and memory 322. As those of skill in the art will realize, the mobile automation apparatus 103 can also include one or more special purpose controllers or processors and/or FPGAs, in communication with the controller 320, specifically configured to control navigational and/or data capture aspects of the mobile automation apparatus 103.

The apparatus 103 also includes a communications interface 324 interconnected with the controller 320. The communications interface 324 includes any suitable hardware (e.g. transmitters, receivers, network interface controllers and the like) allowing the apparatus 103 to communicate with other devices—particularly the server 101 and, optionally, the mobile device 105—for example via the links 107, and the like. The specific components of the communications interface 324 are selected based on the type of network or other links over which the apparatus 103 is required to communicate, including, but not limited to, the wireless local-area network of the retail environment of the system 100.

The memory 322 stores a plurality of applications, each including a plurality of computer readable instructions executable by the controller 320. The execution of the above-mentioned instructions by the controller 320 configures the apparatus 103 to perform various actions discussed herein. The applications stored in the memory 322 include a control application 328, which may also be implemented as a suite of logically distinct applications. In general, via execution of the control application 328 or subcomponents thereof, the controller 320 is configured to implement various functionality. The controller 320, as configured via the execution of the control application 328, is also referred to herein as the controller 320. As will now be apparent, some or all of the functionality implemented by the controller 320 described below may also be performed by preconfigured hardware elements (e.g. one or more ASICs) rather than by execution of the control application 328 by the controller 320.

The apparatus 103 further includes sensors 330, including, but not limited to, the structured light camera 218, the one or more ultrasound arrays 220, the LIDAR device 221 (and/or any other depth sensing device at the same location), the one or more second structured light cameras 228, and other navigation and/or data acquisition sensors.

The apparatus 103 further includes a navigation module 340 configured to move the apparatus 103 in an environment, for example the environment of the modules 110. The navigation module 340 comprises any suitable combination of motors, electric motors, stepper motors, and the like configured to drive and/or steer the wheels 212, and the like, of the apparatus 103. The apparatus 103 generally includes sensors (e.g. a wheel odometer, an IMU (inertial measurement unit), and the like for measuring distances travelled by the apparatus 103.

Hence, in general, the controller 320 is configured to control the apparatus 103 to: navigate the environment of the module 110 using data from the navigation sensors (which can include, but is not limited to, the structured light cameras 218, 228, the LIDAR device 221 and the one or more ultrasound arrays 220) to control the navigation module 340; and control the data acquisition sensors to acquire sensor data, such as electronic data and/or digital data used for one or more of stock detection, low stock detection, price label verification, plug detection, planogram compliance and the like. For example, while not depicted, the memory 322 further stores a map, and the like, of the environment, which may be used for navigation in conjunction with the navigation sensors. The memory may also store sensor data from the data acquisition sensors that may be transmitted to the server 101 for processing.

In the present example, in particular, the apparatus 103 is configured via the execution of the control application 328 by the controller 320, to avoid obstacles using at least camera data from the structured light camera 218.

Turning now to FIG. 4, before describing the operation of the application 328 to avoid obstacles, certain components of the application 328 will be described in greater detail. As will be apparent to those skilled in the art, in 15 examples the components of the application 328 may be separated into distinct applications, or combined into other sets of components. Some or all of the components illustrated in FIG. 4 may also be implemented as dedicated hardware components (e.g. one or more FPGAs and/or one or more ASICs).

As depicted the application 328 is depicted as receiving camera data 428 (e.g. images) from the structured light camera 218, as well as ultrasound data 420 from the one or more ultrasound arrays 220, LIDAR data 421 from the LIDAR device 221 and further camera data 428 (e.g. images) from the one or more second structured light cameras 228.

The control application 328 includes an obstacle avoider 401. In brief, the obstacle avoider 401 is configured to process one or more of the camera data 418, the ultrasound data 420, the LIDAR data 421 and the further camera data 428 to avoid obstacles.

The obstacle avoider 401 includes: an obstacle detector 410 (also referred to herein simply as a detector 410), a distance determiner 411, and an obstacle avoidance protocol 412. In brief, the detector 410 is configured to process camera data 418 captured by the structured light camera 218 to determine whether an object has been detected or not and, depending on a distance to the object, as determined by the distance determiner 411, the obstacle avoidance protocol 412 is used to control the navigation module 340 to avoid the object. As depicted, the obstacle detector 410 includes a shopping cart detector 410 a configured to process the camera data 418 captured by the structured light camera 218 to determine whether the object includes a shopping cart and, in particular, a top of a shopping cart.

In some embodiments, each of the detector 410 and shopping cart detector 410 a comprises signature data (e.g., sensor output signatures indicative of detecting a shopping cart object) and/or threshold data and/or algorithms respectively associated with detecting objects, including shopping carts, using, for example, each of the camera data 418, the ultrasound data 420, the LIDAR data 421 and the further camera data 428.

One or more of the camera data 418, the ultrasound data 420, the LIDAR data 421 and the further camera data 428 is used by the distance determiner 411 to determine a distance of an object to the apparatus 103 (and/or a respective sensor), which implements any number of distance determining techniques.

Attention is now directed to FIG. 5 which depicts a flowchart representative of an example method 500 for obstacle avoidance and, in particular, shopping cart avoidance. The example operations of the method 500 of FIG. 5 correspond to machine readable instructions that are executed by, for example, the apparatus 103, and specifically by the controller 320 and/or the various components of the control application 328 including, but not limited to, the obstacle avoider 401. Indeed, the example method 500 of FIG. 5 is one way in which the apparatus 103 is configured. However, the following discussion of the example method 500 of FIG. 5 will lead to a further understanding of the apparatus 103, and its various components. However, it is to be understood that in other embodiments, the apparatus 103 and/or the method 500 are varied, and hence need not work exactly as discussed herein in conjunction with each other, and that such variations are within the scope of present embodiments.

Furthermore, the example method 500 of FIG. 5 need not be performed in the exact sequence as shown and likewise, in other embodiments, various blocks may be performed in parallel rather than in sequence. Accordingly, the elements of method 500 are referred to herein as “blocks” rather than “steps.” The example method 500 of FIG. 5 may be implemented on variations of the example apparatus 103, as well.

At block 501, the controller 320 determines whether the structured light camera 218 has detected a top of a shopping cart. For example, the block 501 occurs using the shopping cart detector 410 a in conjunction with camera data 418 from the structured light camera 218, such as by comparing the camera data 418 with sensor output signature that is indicative of detecting a top of a shopping cart object.

At the block 503, when the structured light camera 218 detects the top of the shopping cart, the controller 320 controls the navigation module 340 to implement the obstacle avoidance protocol 412. For example, the obstacle avoidance protocol 412 comprises one or more of: stopping the navigation module 340 (e.g. stopping the apparatus 103), slowing the apparatus 103, and controlling the navigation module 340 to avoid the shopping cart (e.g. steer the apparatus 103 around the shopping cart 603).

The method 500 repeats each time the controller 320 determines that the structured light camera 218 has detected a top of a shopping cart at block 501. Hence, the method 500 generally runs in parallel with other methods at the apparatus 103, including, for example other data detection methods (e.g. for detecting prices, barcodes, and the like) and/or navigation methods.

The method 500 is now described with reference to FIG. 6, which is substantially similar to FIG. 2, with like elements having like numbers, but includes a shopping cart 603 comprising an angled reflective metal lattice 605 and/or mesh, on wheels 612, with a bumper 621, and the like, located at a top of the shopping cart 603. The bumper 621 is generally manufactured from one or more of plastic, rubber, resin, and the like. In other embodiments, however, the bumper 621 is part of the lattice 605, where the bumper 621 is one or more of painted, anodized, scratched, so as to be rendered more detectable, by the structured light cameras 218, 228, than the remainder of the lattice 605. Either way, the bumper 621 is generally a part of a bumper and/or a top rim of the shopping cart 603. In the depicted example, the bumper 621 is further located about 0.8 m above the floor 213 and/or the height of the top of the shopping cart 603 is about 0.8 m. The bumper 621 can be a ring around the top of the shopping cart 603 and can be colloquially referred to as a plastic protector ring.

Furthermore, as depicted, the shopping cart 603 is located in a region being imaged by the structured light cameras 218, 228, and the LIDAR device 221. The behavior of the ultrasound arrays 220 is described below.

As depicted, the LIDAR device 221 is attempting to depth scan the wheels 612 (as indicated by the dotted line extending from the LIDAR device 221), and the two or more further structured light cameras 228 are attempting to image the metal lattice 605. However, as the wheels 612 are generally inset from an outside perimeter of the shopping cart 603 (e.g. due to the angle of the lattice 605, which widens from bottom to top) and/or the wheels 612 occupy only a portion of the space under the shopping cart 603, a depth detection of the wheels 612 by the LIDAR device 221 is generally a poor indication of the position of the shopping cart 603; in other words, a front edge of the shopping cart could collide with the apparatus 103 prior to the wheels 612 being detected.

Similarly, the two or more structured light cameras 228 are imaging (as indicated by the dotted lines extending from the two or more structured light cameras 228) the metal lattice 605, which generally is both specularly reflective of light (e.g. the structured light projected by the two are more structured light cameras 228) and includes various air gaps between the metal portions of the lattice which provide no reflections. Hence, the imaging of the metal lattice by the two or more structured light cameras 228 is generally prone to error and/or can be unreliable.

However, due to the location and orientation of the structured light camera 218, the structured light camera 218 is configured to detect at least a top of the shopping cart 603, and in particular the non-reflective bumper 621, in a region adjacent to the mobile automation apparatus 103. As the bumper 621 is not specularly reflective, and is also a solid piece (e.g. lacking air gaps), the camera data 418 from the structured light camera 218 provides a more reliable indication of whether there is a shopping cart adjacent the apparatus 103.

In any event, once the shopping cart 603 is detected by the structured light camera 218, as determined using, for example, the shopping cart detector 410 a, the controller 320 controls the navigation module 340 to stop and/or slow down and/or navigate around the shopping cart 603. For example, the navigation module 340 moves the apparatus 103 to a new path that goes around the shopping cart 603 (e.g. as depicted in FIG. 9).

The region where the top of the shopping cart 603 is detectable by the structured light camera 218 is generally controlled by adjusting the height and orientation of the structured light camera 218. For example, by raising the structured light camera 218 on the mast 214, and/or increasing the angle of the structured light camera 218 outwards from the mast 214, the structured light camera 218 detects the shopping cart 603 when it is further from the apparatus 103; similarly, by lowering the structured light camera 218 on the mast 214, and/or decreasing the angle of the structured light camera 218 inwards, the structured light camera 218 detects the shopping cart 603 when it is closer to the apparatus 103. The structured light camera 218 is, however, at a height and orientation where the bumper 621 of the shopping cart 603 is in a field of view of the structured light camera 218. Hence, in general, the height and orientation of the structured light camera 218 is based on a height of a shopping cart and a distance at which the shopping cart is to be detected. In the depicted embodiments, the shopping cart 603 is about 0.8 m high, and the structured light camera 218 is at a height of about 1.5 m, and an angle of about 45°±5°; hence the shopping cart 603 is detectable about 1 m away from the apparatus 103, which is a sufficient distance for the apparatus 103 to navigate around the shopping cart 603 when detected. However other heights and orientations are within the scope of present embodiments.

In some embodiments, the one or more ultrasound arrays 220 are used to determine a false negative at the structured light camera 218 and/or the second structured light cameras 228. For example, in some instances, including when a reflective metal lattice 605 is within their fields of view, the structured light cameras 218, 228 may not detect a shopping cart and/or other object and/or obstacle. As such, the one or more ultrasound arrays 220 are used at least as a secondary level of obstacle detection.

Hence, attention is now directed to FIG. 7 which depicts a flowchart representative of an example method 700 for avoidance of obstacles having reflective and/or discontinuous (e.g., meshed or lattice-like) surfaces. The example operations of the method 700 of FIG. 7 correspond to machine readable instructions that are executed by, for example, the apparatus 103, and specifically by the controller 320 and/or the various components of the control application 328 including, but not limited to, the obstacle avoider 401. Indeed, the example method 700 of FIG. 7 is one way in which the apparatus 103 is configured. However, the following discussion of the example method 700 of FIG. 7 will lead to a further understanding of the apparatus 103, and its various components. However, it is to be understood that in other embodiments, the apparatus 103 and/or the method 700 are varied, and hence need not work exactly as discussed herein in conjunction with each other, and that such variations are within the scope of present embodiments.

Furthermore, the example method 700 of FIG. 7 need not be performed in the exact sequence as shown and likewise, in other embodiments, various blocks may be performed in parallel rather than in sequence. Accordingly, the elements of method 700 are referred to herein as “blocks” rather than “steps.” The example method 700 of FIG. 7 may be implemented on variations of the example apparatus 103, as well.

At block 701, the controller 320 determines when the one or more ultrasound arrays 220 detect a reflective object and/or an object having discontinuous planar surfaces (e.g., a reflective metal lattice 605 of the cart 603), and the structured light cameras 218, 228 simultaneously do not detect the object. For example, the block 701 occurs using the obstacle detector 410 in conjunction with one or more sets of camera data 418, 428 from at least one of the structured light cameras 218, 228.

At the block 702, the controller 320 determines whether the reflective object is within a threshold distance using, for example, the distance determiner 411 in conjunction with one or more sets of the ultrasound data 420 and/or the LIDAR data 421 (e.g. presuming that the one or more sets of camera data 418, 428 indicate that the object is not detected). In some embodiments, the threshold distance is set to a minimum distance at which the apparatus 103 is navigable around the object.

Furthermore, the block 702 is, in some embodiments, optional, and whether or not the block 702 is implemented is configurable at the apparatus 103.

When the object is not within the threshold distance (e.g. a “No” decision at the block 702), the block 701 repeats whenever an object is detected by the one or more ultrasound arrays 220. In particular, at the block 701, a determination of whether an object and the like is detected occurs periodically (for example, about every 100 ms) and, in some of these embodiments, a local “map” around the apparatus 103 is determined based on data from the structured light cameras 218, 228, the lidar device 221, the ultrasound arrays 220 and/or any other sensors used for detecting obstacles. The local “map” generally represents an obstacle landscape around the apparatus 103. In some of these embodiments, each cell of an occupancy grid (e.g. with cells of about 5 cm×5 cm) of the local map is reviewed by the controller 320 to determine whether or not an obstacle is present in each cell, according to the data received from the from the structured light cameras 218, 228, the lidar device 221, the ultrasound arrays 220. In these embodiments, the data from the ultrasound arrays 220 indicate an obstacle in a given cell, while the data from one or more of the structured light cameras 218, 228 indicate that there is no obstacle in the same given cell. However, other techniques for determining whether obstacles are detected by one or more of the ultrasound arrays 220, but not by at least one of the structured light cameras 218, 228 are within the scope of present embodiments.

However, when the object is within the threshold distance (e.g. a “Yes” decision at the block 702), at the block 703, the controller 320 controls the navigation module 340 to implement the obstacle avoidance protocol 412 as described above with respect to the block 503 of the method 500. Indeed, put another way, the ultrasound arrays 220 are used to detect a false negative of the structured light cameras 218, 228 including, but not limited to, a false negative when detecting a shopping cart, or any other object having reflective and/or discontinuous surfaces (e.g., mesh surfaces) within a field of view of the structured light cameras 218, 228.

In some embodiments, when the structured light cameras 218, 228 provide an indication that an object is detected, corresponding data from the one or more ultrasound arrays 220 is ignored and/or not used. Indeed, as the ultrasounds arrays 220 generally provide a lower resolution of detection than the structured light cameras 218, 228 (e.g. ultrasound images are generally lower resolution than structured light camera images), in some embodiments, the controller 320 ignores ultrasound data when the structured light cameras 218, 228 detect an obstacle (e.g., to reduce use of processing resources and/or reduce processing overhead in obstacle detection).

In some embodiments, the control of the navigation module 340 further depends on the distance to the object. For example, when the object is within a first threshold distance, where the apparatus 103 is not navigable around the object and/or where a collision with the object may occur, the navigation module 340 is controlled to stop and/or slow down the apparatus 103. Similarly, when the object is within a second threshold distance, greater than the first threshold distance, where the apparatus 103 is navigable around the object, the navigation module 340 is controlled to navigate the apparatus 103 around the object. When the embodiment of block 703 causes the apparatus 103 to stop and/or slow down, once the object is at least at the second threshold distance (presuming the object is moving), the navigation module 340 is controlled to navigate the apparatus 103 around the object.

However, if the distance to the object does not change, and the apparatus 103 is stopped, in some embodiments the controller 320 controls the interface 324 to transmit a notification to the server 101 that the apparatus 103 has stopped. In an embodiment, the notification includes a location of the apparatus 103. Upon receipt of the notification, the server 101 transmits a notice to the mobile device 105 that the apparatus 103 is stopped and may also notify the mobile device 105 of the location of the apparatus 103; this can cause a user of the mobile device 105 to investigate why the apparatus 103 has stopped.

Alternatively, if the distance to the object does not change, and the apparatus 103 is stopped, after a given time period, the navigation module 340 is controlled to navigate the apparatus 103 to a position, relative to the object, where the object is at least at the second threshold distance (for example by moving the apparatus 103 in an opposite direction to a movement direction where the object was detected), and the apparatus 103 navigates around the object.

The method 700 repeats each time the controller 320 determines that the one or more ultrasound arrays 220 detects an object, and the structured light cameras 218, 228 simultaneously do not detect the object. Hence, the method 700 generally runs in parallel with other methods at the apparatus 103, including, for example other data detection methods (e.g. for detecting prices, barcodes, and the like) and/or navigation methods.

Indeed, the method 700 is generally executed in parallel with the method 500 and, in some embodiments, the method 500 is modified to include aspects of the method 700. For example, in some embodiments, the method 500 is modified such that when the one or more ultrasound arrays 220 detects an object, for example the shopping cart 603, and the structured light camera 218 simultaneously does not detect the object, for example the shopping cart 603, the navigation module 340 is controlled to implement the obstacle avoidance protocol 412 and/the navigation module 340 is controlled to implement the obstacle avoidance protocol only when the object is within a threshold distance as described above.

The method 700 is now described with reference to FIG. 8, which is substantially similar to FIG. 6, with like elements having like numbers, but includes an object 803. For example, as depicted, the object 803 includes a person; however, the object 803 may also include a shopping cart and/or a person pushing a shopping cart, and/or any other obstacle that the apparatus 103 may encounter in an environment in which the apparatus 103 is navigating. The object 803 is at a distance from the apparatus 103 where the object 803 is not detectable by the structured light cameras 218, 228, but is generally detectable by one or more of the ultrasound arrays 220. The field of view of each of the ultrasound arrays 220 is indicated by broken lines (for clarity, different from the broken lines of the fields of view of the structured light cameras 218, 228 and the LIDAR device 221).

As the structured light cameras 218, 228 do not detect the object 803, but one or more of the ultrasound arrays 220 do detect the object 803, the obstacle avoidance protocol 412 is implemented, as described above. For example, attention is directed to FIG. 9 which schematically depicts a top view of the apparatus 103 and the object 803, as well as a path 901, 903 of the apparatus 103. Specifically, the path 901 represents the path of the apparatus 103 to a location where the object 803 is detected, and the path 903 represents the path of the apparatus 103 from the location where the object 803 is detected when the obstacle avoidance protocol 412 is implemented to navigate around the object 803. In particular, the apparatus 103 is navigated to a path 903 parallel to path 901, until the apparatus 103 is past the object 803, where the apparatus 103 is navigated back to a path coincident with the path 901. Put another way, the navigation module 340 is controlled to alter the navigation of the mobile automation apparatus 103 based on a comparison between ultrasound sensor data (e.g. from an ultrasound sensor 220) to structured light data (e.g. from one or more of the structured light cameras 218, 228). In some embodiments, the apparatus further transmits a notification of the alteration of the path (e.g. from the path 901 to the path 903) to the server 101, which may include a location of the apparatus 103.

In yet further embodiments, the controller 320 can be configured to recognize obstacle types; for example, when the object 803 comprises a shopping cart, a person, a display, and/or any object having a particular physical configuration that can be determined from data from the one or more of the ultrasound arrays 220 and/or the lidar device 221, the obstacle avoidance protocol can be object specific. For example, when the object 803 includes a person, the apparatus 103 can stop; however, when the object 803 includes a shopping cart (e.g. without a person), display, a pallet, and the like, the apparatus 803 can go around the object 803.

In the foregoing specification, specific embodiments have been described. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the invention.

For example, the method 700 is modified, in some embodiments, to control the navigation module 340 to implement the obstacle avoidance protocol 412 when one or more of the structured light cameras 218, 228 and/or the LIDAR device 221 detect an object regardless of whether the one or more ultrasound arrays 220 detect the object. In other words, in some embodiments, the navigation module 340 to implement the obstacle avoidance protocol 412 whenever one or more of the structured light cameras 218, 228, the ultrasound arrays and the LIDAR device 221 detects an object, regardless of whether the other sensors detect an object.

For example, while each of the structured light cameras 218, 228 are described as facing in a forward direction (e.g. in a direction of movement of the apparatus 103), in another example, one or more of the structured light cameras 218, 228 are pointed in other directions, and/or the apparatus 103 further comprises other structured light cameras facing in other directions.

Furthermore, the fields of view of the structured light cameras 218, 228 are arranged, in some embodiments, such that a field of view of the structured light camera 218 is in a dead zone of the fields of view of the structured light cameras 228. For example, attention is next directed to FIG. 10 which schematically depicts the two structured light cameras 228 at the mast 214 (depicted in cross-section), as well as respective fields of views of the two structured light cameras 228 as broken lines extending therefrom. As the two structured light cameras 228 are pointing in different directions, their field of view do not overlap and indeed, there is a dead zone 1001 therebetween where objects are not imaged by the two structured light cameras 228. For example, the dead zone 1001 is, in some embodiments, in a direction of movement of the apparatus 103. However, the field of view 1003 of the structured light camera 218 (not depicted, but assumed to be oriented relative to the two structured light camera 228 as depicted in FIG. 2) is oriented in the dead zone 1001 of the two structured light cameras 228 such that objects not imaged by the two structured light cameras 228 are imaged by the structured light camera 218.

Indeed, such an arrangement can ensure that objects in a region adjacent to the apparatus 103 are detectable by the structured light camera 218, and that objects on either side of this region are detectable by the structured light cameras 228, Indeed, the relative orientations of the structured light cameras 218, 228, as well as the orientations of one or more LIDAR devices and/or depth sensing devices, and/or ultrasound arrays, are generally selected to increase a range over which objects around the apparatus 103 are detectable.

Furthermore, as the structured light camera 218 is pointed towards the floor 213, the structured light camera 218 further detects objects that are above or below the fields of view of each of the LIDAR device 221, the ultrasound arrays 220, and the structured light camera 228.

Indeed, as the apparatus 103 is, in some embodiments, configured to navigate in many directions, the sensors at the apparatus 103 are generally arranged to sense objects over the directions in which the apparatus 103 is configured to navigate.

For example, in some embodiments, the apparatus 103 is configured to move only longitudinally (e.g. forward and backward, as well as steering and/or turning in each of these directions) but not sideways (e.g. non-holonomic). In these embodiments, the sensors at the apparatus 103 are generally arranged to cover a range around the apparatus 103 over which the apparatus 103 is configured to move.

For example, the sensors described herein do not necessarily detect an entirety of an object and/or an obstacle, but rather the sensors are arranged to detect a portion and/or a region of the obstacle in order to infer structure sufficient to implement the obstacle avoidance protocol. Indeed, the sensors described herein are generally low cost readily available sensors, which are arranged to work together so that forward facing regions (e.g. in a movement direction) are generally covered by the sensors. For example, if LIDAR does not detect any part of an obstacle, then a structured light camera may detect part of the obstacle; however, if the structured light camera does not detect part of the obstacle, then the ultrasound arrays should detect at least a part of the obstacle. In other words, as the apparatus 103 is provisioned with three types of sensors for obstacle detection, the obstacle avoider 401 includes primary, secondary, and tertiary levels of obstacle detection.

The LIDAR devices described herein may have difficulties detecting light absorbing (black/dark) materials or highly reflective materials. Furthermore, the LIDAR devices described herein may be 2D (two-dimensional) planar sensors, which hence detect obstacles over a slice of the environment in which the apparatus 103 is navigating, and at ankle level.

Structured light cameras described herein may have difficulties detecting light absorbing (black/dark) materials or highly reflective materials. However, structured light cameras can otherwise detect a large percentage of the obstacles found in the retail environment. Ultrasound arrays and/or sensors may have issues detecting obstacles with high resolution since the sound waves are directed over a wide angle. However, ultrasound arrays and/or sensors very accurately detect highly reflective materials or very small objects.

Hence, in the apparatus described herein, a LIDAR device mounted at a front of the apparatus at ankle height is used to detect a large majority of the obstacles found at ankle height. Any obstacle found above or below ankle height is to be detected using a different sensor modality. Multiple structured light cameras (e.g. structured light cameras 228) are used to detect shoppers, aisle shelves, doors, baskets, shopping carts, items protruding from shelf, and any obstacle that is more than 1 m away from the apparatus 103 (and/or outside of a field of view of the structured light camera 218) and is in the range of the structured light cameras 228. However, in order to detect a shopping cart, the structured light camera 218 is placed at a height of about 1.5 m angled downwards at about 45 degrees, which allows for detecting a plastic protector ring on the top of a shopping cart. From the camera data captured by the structured light camera 228, at least the plastic protector ring of the shopping cart is detectable which allows the shopping cart to be avoided by the apparatus 103, as per the method 500.

However, as a failsafe, as per the method 700, the one or more ultrasound arrays 220 are used to detect obstacles within close proximity to the apparatus 103, for example, which, when detected, can cause the apparatus to stop and/or slow down (and/or prepare to stop and/or slow down), for example, when the obstacle is about 1 m from the apparatus 103. Indeed, the ultrasound sensors of the one or more ultrasound arrays 220 are, in some embodiments, positioned to form a phased ultrasound array which can detect shiny reflective obstacles such as reflective shopping cart meshes and/or lattices, within 1 m from the apparatus 103. Indeed, phased ultrasound array can further increase the obstacle detection resolution.

In the foregoing specification, specific embodiments have been described. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the invention as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of present teachings.

The benefits, advantages, solutions to problems, and any element(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential features or elements of any or all the claims. The invention is defined solely by the appended claims including any amendments made during the pendency of this application and all equivalents of those claims as issued.

Moreover, in this document, language of “at least one of X, Y, and Z” and “one or more of X, Y and Z” can be construed as X only, Y only, Z only, or any combination of two or more items X, Y, and Z (e.g., XYZ, XY, YZ, XZ, and the like). Similar logic can be applied for two or more items in any occurrence of “at least one . . . ” and “one or more . . . ” language.

Moreover in this document, relational terms such as first and second, top and bottom, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms “comprises,” “comprising,” “has”, “having,” “includes”, “including,” “contains”, “containing” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises, has, includes, contains a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by “comprises . . . a”, “has . . . a”, “includes . . . a”, “contains . . . a” does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises, has, includes, contains the element. The terms “a” and “an” are defined as one or more unless explicitly stated otherwise herein. The terms “substantially”, “essentially”, “approximately”, “about” or any other version thereof, are defined as being close to as understood by one of ordinary skill in the art, and in one non-limiting embodiment the term is defined to be within 10%, in another embodiment within 5%, in another embodiment within 1% and in another embodiment within 0.5%. The term “coupled” as used herein is defined as connected, although not necessarily directly and not necessarily mechanically. A device or structure that is “configured” in a certain way is configured in at least that way, but may also be configured in ways that are not listed.

It will be appreciated that some embodiments may be comprised of one or more generic or specialized processors (or “processing devices”) such as microprocessors, digital signal processors, customized processors and field programmable gate arrays (FPGAs) and unique stored program instructions (including both software and firmware) that control the one or more processors to implement, in conjunction with certain non-processor circuits, some, most, or all of the functions of the method and/or apparatus described herein. Alternatively, some or all functions could be implemented by a state machine that has no stored program instructions, or in one or more application specific integrated circuits (ASICs), in which each function or some combinations of certain of the functions are implemented as custom logic. Of course, a combination of the two approaches could be used.

Moreover, an embodiment can be implemented as a computer-readable storage medium having computer readable code stored thereon for programming a computer (e.g., comprising a processor) to perform a method as described and claimed herein. Examples of such computer-readable storage mediums include, but are not limited to, a hard disk, a CD-ROM, an optical storage device, a magnetic storage device, a ROM (Read Only Memory), a PROM (Programmable Read Only Memory), an EPROM (Erasable Programmable Read Only Memory), an EEPROM (Electrically Erasable Programmable Read Only Memory) and a Flash memory. Further, it is expected that one of ordinary skill, notwithstanding possibly significant effort and many design choices motivated by, for example, available time, current technology, and economic considerations, when guided by the concepts and principles disclosed herein will be readily capable of generating such software instructions and programs and ICs with minimal experimentation.

The Abstract of the Disclosure is provided to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, it can be seen that various features are grouped together in various embodiments for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separately claimed subject matter. 

We claim:
 1. A mobile automation apparatus comprising: a mast extending in an upward direction; a navigation module configured to move the mobile automation apparatus in an environment; a structured light camera positioned on the mast, the structured light camera configured to detect at least a top of a shopping cart in a region adjacent to the mobile automation apparatus; one or more ultrasound arrays on the mast, each of the one or more ultrasound arrays configured to detect an object at least in the region; and a controller configured to implement an obstacle avoidance protocol when the one or more ultrasound arrays detect the object and the structured light camera simultaneously does not detect the object.
 2. The mobile automation apparatus of claim 1, wherein the object includes a reflective surface.
 3. The mobile automation apparatus of claim 2, wherein the surface is discontinuous.
 4. The mobile automation apparatus of claim 3, wherein the surface is a mesh surface of the shopping cart.
 5. The mobile automation apparatus of claim 1, further comprising a base, the mast extending in the upward direction from the base; and one or more of a depth sensing device and a LIDAR device located at the base, and configured to sense depth at an ankle height.
 6. The mobile automation apparatus of claim 1, further comprising one or more second structured light cameras between a base of the mast and the structured light camera, the one or more second structured light cameras configured to detect objects over respective angles on either side of the region.
 7. The mobile automation apparatus of claim 1, wherein the controller is further configured to: when the one or more ultrasound arrays detect the object, and the structured light camera simultaneously does not detect the object, control the navigation module to implement the obstacle avoidance protocol only when the object is within a threshold distance.
 8. The mobile automation apparatus of claim 1, wherein the navigation module is configured to move the mobile automation apparatus in the environment in a forward direction, and the structured light camera is further configured to detect at least the top of the shopping cart in the region in the forward direction.
 9. The mobile automation apparatus of claim 1, further comprising a communication interface configured to transmit a notification of an alteration of a navigation of the mobile automation apparatus to a mobile device.
 10. The mobile automation apparatus of claim 9, wherein the notification includes a location of the mobile automation apparatus.
 11. A method of obstacle avoidance by a mobile automation apparatus, the method comprising: detecting an object in a region in a vicinity of the mobile automation apparatus by an ultrasound sensor in the mobile automation apparatus when a structured light camera in the mobile automation apparatus simultaneously does not detect the object in the region; determining whether the object is within a threshold distance from the mobile automation apparatus; and implementing an obstacle avoidance protocol by the mobile automation apparatus in response to detecting the object by the ultrasound sensor when the object is within the threshold distance and the structured light camera simultaneously does not detect the object.
 12. The method of claim 11, wherein the object includes a reflective surface.
 13. The method of claim 12, wherein the surface is discontinuous.
 14. The method of claim 13, wherein the surface is a mesh surface.
 15. The method of claim 14, wherein the mesh surface is a surface of a shopping cart.
 16. The method of claim 11, further comprising transmitting a notification of an alteration of a navigation of the mobile automation apparatus to a mobile device.
 17. The method of claim 16, wherein the notification includes a location of the mobile automation apparatus.
 18. A non-transitory computer readable medium having stored thereon computer executable instructions for obstacle avoidance by a mobile automation apparatus, the instructions comprising: detecting an object in a region in a vicinity of the mobile automation apparatus by an ultrasound sensor in the mobile automation apparatus when a structured light camera in the mobile automation apparatus simultaneously does not detect the object in the region; determining whether the object is within a threshold distance from the mobile automation apparatus; and implementing an obstacle avoidance protocol by the mobile automation apparatus in response to detecting the object by the ultrasound sensor when the object is within the threshold distance and the structured light camera simultaneously does not detect the object.
 19. The computer readable medium of claim 18, wherein the object includes a reflective surface.
 20. The computer readable medium of claim 19, wherein the reflective surface is a mesh surface of a shopping cart. 